LM2738XMYEVAL

www.ti.com Table of Contents User’s Guide LM2738 Step-Down Converter Evaluation Module User's Guide Table of Contents 1 Introduction.............................................................................................................................................................................2 2 Operating Conditions............................................................................................................................................................. 2 3 PCB Layout - WSON............................................................................................................................................................... 4 4 PCB Layout - MSOP-PowerPAD............................................................................................................................................ 6 5 Additional Circuit Configuration Schematics...................................................................................................................... 8 6 Revision History....................................................................................................................................................................11 List of Figures Figure 2-1. LM2738 Demo Board Schematic - VBOOST Derived from VOUT = 3.3 V, VIN = 12 V.................................................. 2 Figure 2-2. Efficiency vs Load Current - VIN = 12 V, VOUT = 3.3 V.............................................................................................. 2 Figure 3-1. Top Layer...................................................................................................................................................................4 Figure 3-2. Internal Plane - Layer 2 (GND)..................................................................................................................................4 Figure 3-3. Internal Plane - Layer 3 (GND)..................................................................................................................................5 Figure 3-4. Bottom Layer............................................................................................................................................................. 5 Figure 4-1. Top Layer...................................................................................................................................................................6 Figure 4-2. Internal Plane - Layer 2 (GND)..................................................................................................................................6 Figure 4-3. Internal Plane - Layer 3 (GND)..................................................................................................................................7 Figure 4-4. Bottom Layer............................................................................................................................................................. 7 Figure 5-1. VBOOST Derived from VIN = 5 V, for VOUT = 1.5 V...................................................................................................... 8 Figure 5-2. VBOOST Derived from VSHUNT Coming from VIN = 18 V, VOUT = 1.5 V.......................................................................9 Figure 5-3. VBOOST Derived from Series Zener Diode from VIN = 15 V, VOUT = 1.5 V............................................................... 10 Figure 5-4. VBOOST Derived from Series Zener Diode from VOUT = 9 V, VIN = 15 V.................................................................. 11 List of Tables Table 2-1. Bill of Materials X-Version (1.6 MHz).......................................................................................................................... 3 Table 2-2. Bill of Materials Y-Version (550 kHz)...........................................................................................................................3 Table 5-1. Bill of Materials X-Version (1.6 MHz).......................................................................................................................... 8 Table 5-2. Bill of Materials Y-Version (550 kHz)...........................................................................................................................8 Table 5-3. Bill of Materials X-Version (1.6 MHz).......................................................................................................................... 9 Table 5-4. Bill of Materials Y-Version (550 kHz)...........................................................................................................................9 Table 5-5. Bill of Materials X-Version (1.6 MHz)........................................................................................................................ 10 Table 5-6. Bill of Materials Y-Version (550 kHz).........................................................................................................................10 Table 5-7. Bill of Materials X-Version (1.6 MHz).........................................................................................................................11 Table 5-8. Bill of Materials Y-Version (550 kHz)......................................................................................................................... 11 Trademarks All trademarks are the property of their respective owners. SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 LM2738 Step-Down Converter Evaluation Module User's Guide Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated 1 Introduction www.ti.com 1 Introduction The LM2738 demo board is configured to convert 12-V input to 3.3-V output at 1.5-A load current using the LM2738X 1.6-MHz or the LM2738Y 550-kHz step down DC-DC regulator. The tiny low profile MSOPPowerPAD-8 and WSON-8 packages allows the demo board to be manufactured using just over one square inch of a 4-layer printed circuit board. The circuit is configured with the boost diode connected to VOUT, and according to the data sheet, VOUT must not exceed the maximum operating limit of 5.5 V + VfD2 using this configuration. This makes sure that the voltage between the boost and SW pins, VBOOST–VSW, does not exceed 5.5 V for proper operation. Please see the LM2738 550kHz/1.6MHz 1.5A Step-Down DC-DC Switching Regulator data sheet for more information regarding this requirement. A bill of materials describes the parts used on this demo board. A schematic and layout have also been included along with measured performance characteristics. The schematics at the end of this document show how to re-configure this demo board for various input and output conditions as discussed in the LM2738 550kHz/ 1.6MHz 1.5A Step-Down DC-DC Switching Regulator data sheet. Short or leave open the indicated connection as indicated in the schematics. The above restrictions for the input voltage are valid only for the demo board as shipped with the demo board schematic (see Figure 2-1). 2 Operating Conditions • • • VIN = 12 V VO = 3.3 V IO = 1.5 A Figure 2-1. LM2738 Demo Board Schematic - VBOOST Derived from VOUT = 3.3 V, VIN = 12 V Figure 2-2. Efficiency vs Load Current - VIN = 12 V, VOUT = 3.3 V 2 LM2738 Step-Down Converter Evaluation Module User's Guide SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated www.ti.com Operating Conditions Table 2-1. Bill of Materials X-Version (1.6 MHz) Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 C2, C5, Output Cap 22 µF, 10 V, X5R TDK C3216X5R1A226 1206 C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5-A Buck Regulator Texas Instruments LM2738 MSOP-PowerPAD-8 D1, Catch Diode 0.34-VF Schottky, 1.5 A, 30 VR Toshiba CRS08 - L1 5.0 µH, 2.9 A Coilcraft MSS7341-502NL - R1 31.6 kΩ, 1% Vishay CRCW12063162F 0805 R5 0Ω Vishay CRCW12060R00F 0805 D4, R4 Open or No Load Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 C2, C5, Output Cap 22 µF, 10 V, X5R TDK C3216X5R1A226 1206 Table 2-2. Bill of Materials Y-Version (550 kHz) C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100 mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5-A Buck Regulator Texas Instruments LM2738 MSOP-PowerPAD-8 D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30 VR Toshiba CRS08 - L1 10.0 µH, 2.0 A Coilcraft MSS7341-103NL - R1 31.6 kΩ, 1% Vishay CRCW12063162F 0805 R5 0Ω Vishay CRCW12060R00F 0805 D4, R4 Open or No Load SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 LM2738 Step-Down Converter Evaluation Module User's Guide Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated 3 PCB Layout - WSON www.ti.com 3 PCB Layout - WSON Figure 3-1. Top Layer Figure 3-2. Internal Plane - Layer 2 (GND) 4 LM2738 Step-Down Converter Evaluation Module User's Guide SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated www.ti.com PCB Layout - WSON Figure 3-3. Internal Plane - Layer 3 (GND) Figure 3-4. Bottom Layer SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 LM2738 Step-Down Converter Evaluation Module User's Guide Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated 5 PCB Layout - MSOP-PowerPAD www.ti.com 4 PCB Layout - MSOP-PowerPAD Figure 4-1. Top Layer Figure 4-2. Internal Plane - Layer 2 (GND) 6 LM2738 Step-Down Converter Evaluation Module User's Guide SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated www.ti.com PCB Layout - MSOP-PowerPAD Figure 4-3. Internal Plane - Layer 3 (GND) Figure 4-4. Bottom Layer SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 LM2738 Step-Down Converter Evaluation Module User's Guide Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated 7 Additional Circuit Configuration Schematics www.ti.com 5 Additional Circuit Configuration Schematics Figure 5-1. VBOOST Derived from VIN = 5 V, for VOUT = 1.5 V Table 5-1. Bill of Materials X-Version (1.6 MHz) Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R C2, Output Cap 22 µF, 6.3 V, X5R TDK C3216X5R1E106 1206 TDK C3216X5R0J2266 1206 C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 LM2738 WSON-8 LM2738 MSOP-PowerPAD-8 U1 1.5-A Buck Regulator Texas Instruments D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30 V Toshiba CRS08 - L1 2.2 µH, 1.9A Coilcraft MSS5131-222ML - R1 8.87 kΩ, 1% Vishay CRCW12068871F 0805 R4 0Ω Vishay CRCW12060R00F 0805 D4, R5, C5 Open or No Load Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 C2, C5, Output Caps 22 µF, 6.3 V, X5R TDK C3216X5R0J226 1206 C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 U1 1.5-A Buck Regulator Texas Instruments D1, Catch Diode 0.34 VF Schottky ,1.5 A, 30 V L1 Table 5-2. Bill of Materials Y-Version (550 kHz) 8 LM2738 WSON-8 LM2738 MSOP-PowerPAD-8 Toshiba CRS08 - 6.2 µH, 2.5 A Coilcraft MSS7341-622NL - R1 8.87 kΩ, 1% Vishay CRCW12068871F 0805 R4 0Ω Vishay CRCW12060R00F 0805 D4, R5 Open or No Load LM2738 Step-Down Converter Evaluation Module User's Guide SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated www.ti.com Additional Circuit Configuration Schematics Figure 5-2. VBOOST Derived from VSHUNT Coming from VIN = 18 V, VOUT = 1.5 V Table 5-3. Bill of Materials X-Version (1.6 MHz) Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25V, X7R TDK C3216X5R1E106 1206 C2, C5, Output Caps 22 µF, 6.3V, X5R TDK C3216X5R0J226 1206 C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 D4, Zeneer 5.1 V, 200 mW Diodes, Inc. BZX84C5V1W SOT-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5-A Buck Regulator Texas Instruments LM2738 MSOP-PowerPAD-8 D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30 V Toshiba CRS08 - L1 2.7 µH, 1.76 A TDK VLCF5020T-2R7N1R7 - R1 8.87 kΩ, 1% Vishay CRCW12068871F 0805 R4 4.12 kΩ, 1% Vishay CRCW12064121F 0805 R5 Open or No Load Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 C2, C5, Output Caps 47 µF, 6.3 V, X5R TDK C3216X5R0J476 1206 Table 5-4. Bill of Materials Y-Version (550 kHz) C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 D4, Zeneer 5.1 V, 200 mW Diodes, Inc. BZX84C5V1W SOT-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 U1 1.5-A Buck Regulator Texas Instruments D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30 V L1 8.7 µH, 2.2 A R1 8.87 kΩ, 1% R4 4.21 kΩ, 1% R5 Open or No Load LM2738 WSON-8 LM2738 MSOP-PowerPAD-8 Toshiba CRS08 - Coilcraft MSS7341-872NL - Vishay CRCW12068871F 0805 Vishay CRCW12064211F 0805 SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 LM2738 Step-Down Converter Evaluation Module User's Guide Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated 9 Additional Circuit Configuration Schematics www.ti.com Figure 5-3. VBOOST Derived from Series Zener Diode from VIN = 15 V, VOUT = 1.5 V Table 5-5. Bill of Materials X-Version (1.6 MHz) Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 C2, C5, Output Caps 22 µF, 6.3 V, X5R TDK C3216X5R0J226 1206 C3 (Boost Cap) 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 LM2738 WSON-8 LM2738 MSOP-PowerPAD-8 U1 1.5-A Buck Regulator Texas Instruments D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30 V Toshiba CRS08 - L1 3.3 µH, 3.5 A Coilcraft MSS7341-332NL - R1 8.87 kΩ, 1% Vishay CRCW12068871F 0805 R4 11 V, 200 mW, Zener Vishay BZX384C11-V SOD-323 D4, R5, C4 Open or No Load Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 C2, C5, Output Caps 47 µF, 6.3 V, X5R TDK C3216X5R0J476 1206 C3 (Boost Cap) 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 U1 1.5-A Buck Regulator Texas Instruments D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30 V L1 8.7 µH, 2.2 A R1 8.87 kΩ, 1% Vishay CRCW12068871F 0805 R4 11 V, 200 mW, Zener Vishay BZX384C11-V SOD-323 D4, R5, C4 Open or No Load Table 5-6. Bill of Materials Y-Version (550 kHz) 10 LM2738 Step-Down Converter Evaluation Module User's Guide LM2738 WSON-8 LM2738 MSOP-PowerPAD-8 Toshiba CRS08 - Coilcraft MSS7341-872NL - SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated www.ti.com Revision History Figure 5-4. VBOOST Derived from Series Zener Diode from VOUT = 9 V, VIN = 15 V Table 5-7. Bill of Materials X-Version (1.6 MHz) Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 C2, Output Cap 22 µF, 10 V, X5R TDK C3216X5R1A226 1206 C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 LM2738 WSON-8 LM2738 MSOP-PowerPAD-8 U1 1.5-A Buck Regulator Texas Instruments D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30 V Toshiba CRS08 - L1 6.2 µH, 2.5 A Coilcraft MSS7341-622NL - R1 102 kΩ, 1% Vishay CRCW1206123F 0805 R5 4.3 V, 200 mW, Zener Vishay BZX384C4V3-V SOD-323 D4, R4 Open or No Load Part ID Part Value Manufacturer Part Number Package Type C1, Input Cap 10 µF, 25 V, X7R TDK C3216X5R1E106 1206 Table 5-8. Bill of Materials Y-Version (550 kHz) C2, Output Cap 22 µF, 10 V, X5R TDK C3216X5R1A226 1206 C3 (Boost Cap), C4 0.1 µF TDK C2012X7R1A104 0805 D2, Boost Diode 1 VF at 100-mA Diode Diodes, Inc. BAT54WS-TP SOD-323 R2, R3 10 kΩ, 1% Vishay CRCW12061002F 0805 U1 1.5-A Buck Regulator Texas Instruments D1, Catch Diode 0.34 VF Schottky, 1.5 A, 30V L1 5.0 µH, 2.9 A R1 102 kΩ, 1% Vishay CRCW12061023F 0805 R5 4.3 V, 200 mW, Zener Vishay BZX384C4V3-V SOD-323 D4, R4 Open or No Load LM2738 WSON-8 LM2738 MSOP-PowerPAD-8 Toshiba CRS08 - Coilcraft MSS7341-502NL - 6 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision A (April 2013) to Revision B (December 2021) Page • Updated the numbering format for tables, figures, and cross-references throughout the document. ................2 SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 LM2738 Step-Down Converter Evaluation Module User's Guide Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated 11 Revision History • • 12 www.ti.com Updated the user's guide title............................................................................................................................. 2 Edited user's guide for clarity..............................................................................................................................2 LM2738 Step-Down Converter Evaluation Module User's Guide SNVA341B – APRIL 2008 – REVISED DECEMBER 2021 Submit Document Feedback Copyright © 2021 Texas Instruments Incorporated IMPORTANT NOTICE AND DISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATA SHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. 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